feat: Upgrade to Python 3.13 and complete MongoDB migration

Major improvements:
- Upgrade Python from 3.10 to 3.13 with updated dependencies
- Complete migration from SQLAlchemy to MongoDB/Beanie ODM
- Fix all type checking errors (MyPy: 0 errors)
- Fix all linting issues (Ruff: 0 errors)
- Ensure code formatting (Black: 100% compliant)

Technical changes:
- pyproject.toml: Update to Python 3.13, modernize dependencies
- models.py: Expand MongoDB models, add enums (ActionRiskLevel, TicketStatus, FeedbackType)
- reliability.py: Complete rewrite from SQLAlchemy to Beanie (552 lines)
- main.py: Add return type annotations, fix TicketResponse types
- agent.py: Add type annotations, fix Anthropic API response handling
- client.py: Add async context manager types
- config.py: Add default values for required settings
- database.py: Update Beanie initialization with all models

All pipeline checks passing:
✅ Black formatting
✅ Ruff linting
✅ MyPy type checking

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.local.json

@@ -0,0 +1,9 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(poetry install --no-root)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}